摘要:
A tire air pressure detection device of the present invention includes a warning anticipation timing calculating portion for anticipating a warning timing at which tire air pressure decrease detecting portion will detect the tire air pressure decrease based on rotational status value compensated for by a rotational status value compensating portion. A tire air pressure decrease detecting portion detects a decrease in tire air pressure when a clocked determination time reaches the warning anticipation timing anticipated by the warning anticipation timing calculating portion.
摘要:
A tire air pressure detection device includes an ideal driving status calculating portion (3e) and a rotational status value compensating portion (3f). The ideal driving status calculating portion calculates an ideal status value (βid) corresponding to a slip value under an ideal driving status without tire slippage. The rational status value compensating portion calculates and ideal rotational status value under the ideal driving status without tire slip based on the regression line calculated by a regression line calculating portion (3d) and the ideal slip status value calculated by the ideal driving status calculating portion.
摘要:
The invention provides an apparatus and a method of estimating tire air pressure with high accuracy from vehicle operation at low at high speeds regardless of various elements to be mounted to the vehicle. Estimation of tire air pressure based on a resonance frequency extracted based on a wheel speed signal outputted from a wheel speed sensor corresponding to the respective tire and estimation of tire air pressure based on a dynamic load radius derived based on the wheel speed signal, are used to selectively switch in accordance with a magnitude of a variance value of the resonance frequency at a plurality of time points.
摘要:
A variable value (dynamic load radial deviation &bgr;) for making determination of a tire air pressure is calculated from pulse number cumulative values PFL, PFR, PRL and PRR that are cumulated for individual wheels when a predetermined condition is fulfilled. The calculated variable value is stored as a reference variable value, and a speed of a vehicle at the time when the reference variable value is calculated is stored as a reference vehicle speed associated with the reference variable value. If the value is newly calculated, it is determined whether or not a vehicle speed at that moment is within a predetermined vehicle speed range determined by the reference vehicle speed. If it is determined that the vehicle speed is within the predetermined vehicle speed range, it is determined, based on a difference between the newly calculated variable value and the reference variable value associated with the reference vehicle speed, whether or not the tire air pressure is normal. Thus, even if the vehicle is fitted with one or more tires that depend greatly on vehicle speed, the possibility of erroneously determining that a tire air pressure is not normal can be eliminated.
摘要:
A tire burst predicting device which can predict occurrence of bursting of a tire and gives an alarm properly is provided. A break point frequency is estimated on the basis of time series data of wheel speed detected at a wheel speed sensor from frequency response of a first order model to which a transmission characteristic from a road surface disturbance to a wheel speed is approximated. A braking force gradient corresponding to the estimated break point frequency is estimated, on the basis of a map, which is prestored, representing a relationship between break point frequencies and braking force gradients. Extra high frequency components are eliminated from the estimated braking force gradient by a low pass filter to reduce estimation dispersion. Differentiators detect changing speed of the braking force gradient. An alarm is given when there is a possibility of bursting of tire when the detected changing speed reaches or exceeds a predetermined threshold value.
摘要:
To accurately detect a resonance frequency of tire even in high speed range by which tire air pressure state of each wheel is known, a calculation processing unit to which detection signals of wheel speed and resonance frequencies of tire are inputted calculates a timewise change amount of a wheel speed deviation that is a difference between wheel speed ratios of front and rear wheels. Then, it makes corrections to remove the influence of timewise change amounts of resonance frequencies of front wheels from timewise change amounts of wheel speed deviations based on a relationship between the resonance frequency and the wheel speed deviation when air pressure of the tire is changed. The unit then converts the corrected timewise change amount of the rotational state into the timewise change amount of the resonance frequencies of the rear wheels based on the above-described relationship and the resonance frequencies of the rear wheels and the timewise change amounts of the resonance frequencies of the rear wheels which have been accurately detected before the vehicle speed exceeds an upper limit value.
摘要:
An apparatus for estimating an air pressure of a tire of a tired wheel of a motor vehicle, on the basis of a temperature of the tire as well as a motion of the tired wheel, preferably including a temperature-related variable sensor for detecting a temperature-related variable related to the temperature of the tire, and an estimating device for estimating the air pressure of the tire on the basis of the temperature-related variable as well as the motion of the tired wheel.
摘要:
A wheel information estimating apparatus, which includes: a detecting device for detecting a wheel motion state relating to a movement of a tired wheel of a motor vehicle; an estimating device for estimating wheel information relating to the tired wheel, on the basis of the wheel motion state detected by the detecting device; and a modifying device for modifying an element relating to estimation of the wheel information, so as to improve an accuracy of estimating the wheel information. The element to be modified is selected from a movement of a center of rotation of the tired wheel as viewed in a plane in which the wheel is rotated, a signal applied from the detecting device to the estimating device, and an internal parameter used by the estimating means for estimating the wheel information.
摘要:
In a tire air pressure estimation based upon vibration components extractedrom a vehicle wheel speed signal, when the vehicle is a driven vehicle wheel, the precision of estimation is improved by canceling the components of vibration due to the resonance of the drive system from the vibration components based upon which the estimation calculation is made. The vibration components due to the resonance of the drive system can be canceled by canceling those vibration components extracted from the vehicle wheel speed signal which are the same in the phase between left and right driven vehicle wheels. When the tire air pressure of one of a pair of left and right driven vehicle wheels is lower than that of the other, the lower tire air pressure is more correctly estimated. Therefore, the higher tire air pressure may be estimated according to the lower tire air pressure against the drive system resonance.
摘要:
A height controlling apparatus for controlling at least one actual height as a relative position of (a) a body of a vehicle and (b) at least one wheel of the vehicle relative to each other, the apparatus including at least one height controlling actuator which changes the at least one actual height; and an actuator control device which controls the at least one height controlling actuator so that the at least one actual height approaches at least one target height. The actuator control device includes a possibility detecting device which detects, before an absolute value of a difference of the at least one target height and the at least one actual height exceeds a reference value, whether there is a possibility that an object may be present in a direction in which the body is moved to change the at least one actual height, and a movement restraining portion which controls, when the possibility detecting device detects that there is the possibility, the at least one height controlling actuator to restrain a movement of the body in the direction.